Warnock, the Leeds boss, is unsure
whether he will complete the pre-match gesture at Elland Road due to a
dispute between the two dating back to 2007 when they were respective
Sheffield United and Liverpool managers.

Benitez was accused by his rival of
playing a weakened team that Warnock felt contributed to United's
relegation from the Barclays Premier League.

Head to head: Rafa Benitez and Neil Warnock (right) have a history

'I'm professional so will do my job. I'm professional, I will behave,' the Spaniard said.

'I'm professional so I won't have any problem (shaking Warnock's hand). There will be a lot of people watching us, so we have to behave.

'I saw that he said he has an email from me threatening to sue hum, but I don't remember. It's true, but I didn't remember it.

'I will concentrate on my job and hopefully we can talk about football, which is best for the fans and everyone. We need to leave things on the pitch.'

Warnock was Sheffield United manager in 2007 when he admitted he would 'never forgive' Benitez for picking what he deemed a weakened team in Liverpool's final away game of the season against Fulham.

The
Blades needed Benitez's Reds to get a result against Fulham, who were
in the relegation zone, but the Londoners won the game 1-0, a result
which saw them survive at the expense of United.

Warnock's criticism of Benitez led to
the Spaniard's legal team sending an email warning of possible legal
action were he to be mentioned again.

Warnock said: 'The last time I heard from Rafa he was threatening to sue me in an email if I mentioned it again.

'Enough water's passed under the bridge. I don't want to give you any more ammunition than you've already got.

'It's
one of those things that disappoints you in life and you have to get on
with it really, but you get disappointments in every walk of life and
I've made my feelings clear on how my feelings have been over the last
few years and nothing will change that.

'I
think it (the email) had his name on, I think it was his solicitor on
who was threatening legal action and I've got it in a scrapbook at home.

'I've no idea (if they will shake hands), I haven't thought about it yet, I was too worried about Ipswich (last Saturday).'

Frank Lampard will start for Chelsea at Elland Road, but Benitez was non-committal over his future with the England midfielder considering his options for the January transfer window.

'Frank is fully committed in every training session and every game. He's an important player for us.

Chelsea travel to Elland Road on the back of a 1-0 loss to Corinthians in the Club World Cup final

'But I can't say too much about what he feels or doesn't feel. He's doing well and I'm happy about his attitude.'

Since losing to Manchester City in the FA Community Shield in mid-August, Chelsea have been found wanting in big matches this season with their Champions League group exit the lowest point yet.

Benitez, who believes the Blues remain in the Premier League title race despite trailing leaders City by 13 points, predicts a change in fortunes soon.

'It's easier to lose in big games because you play against better teams. Normally in finals the other teams are good too,' he said.

'It's just a question of time until we start winning games in a row. We are progressing and are going in the right direction, but we need to be more consistent.

'Winning is especially important for us because when you change the manager and have so many matches you have to win to breed confidence in the new methods. There's no problem with team spirit.'

Game on: Warnock hasn't always seen eye to eye with Benitez but he thinks the Spaniard was right to take the Chelsea job